The present invention is directed to a portable muscle/nerve stimulation system and more particularly to such a system having a programmable channel sequencer with a sufficient number of output channels to which electrodes are coupled to allow a complete programmed therapy to be performed without requiring the electrodes to be moved.
Portable neuro-muscular electrical stimulators have been known to provide a stimulation signal on two channels where each channel is coupled to a pair of electrodes that are attached to the patient's skin so as to stimulate a muscle or nerve. One such stimulator is the NeuroTech NT2000 manufactured and/or sold by Bio-Medical Research Ltd. The stimulation signal of the NT2000 has a contraction cycle and a relaxation cycle, each cycle formed of a number of pulses. The NT2000, in one mode, provides a stimulation signal on each of the two channels at the same time so that the contraction and relaxation cycles coincide but the individual pulses on the two channels are offset. In another mode, the stimulation signal alternates between the two channels. Various parameters of the NT2000 are programmable including frequency, pulse width, contraction cycle, length, relaxation cycle length, ramp up period, ramp down period, amplitude limit and a delay period between the ramp up time on the two channels. The treatment time for one therapy session is also programmable. Upon termination of the treatment time, the unit must be turned off and then turned on to start a new therapy session.
One of the main problems with known neuro-muscular stimulators is that they have a very limited number of output channels. As such, in one therapy session, the electrodes may have to be manually moved a number of times so as to treat different muscles/nerves. Moreover, in many cases, each time the electrodes are moved, the stimulator has to be reprogrammed because the treatment time for various muscles/nerves varies. Known stimulators with more than one channel are still not flexible enough for many applications because the treatment time for each channel is not individually programmable. Instead, it is only the total time that the unit is generating signals that is programmable.
For facial muscle toning, the disadvantages of prior neuro-muscular stimulators is particularly apparent. For facial muscle toning, a large number of electrodes of small diameter is desired. Moreover, the length of time that a given electrode pair should be active can vary considerably from one electrode pair position to another electrode pair position for a single patient as well as from patient to patient. Therefore, one therapy prescription is not suitable for all patients.